During growth of the mammalian oocyte a variety of proteins and messenger-RNAs are synthesized for utilization days-to-weeks later during preimplantation development. We propose to continue our investigations of two specific classes of proteins identified by us during the previous award period, the zona pellucida glycoproteins (ZP1-ZP3) and the "fertilization proteins" (FP1-FP6); the former are synthesized and secreted by growing mouse oocytes, whereas the latter are synthesized in response to fertilization of mouse eggs on mRNA accumulated during oogenesis. ZP1-ZP3 are the glycoprotein components of the zona pellucida, an acellular coat surrounding mammalian eggs that serves important functions during fertilization and preimplantation development. Although the function(s) of the "fertilization proteins" is not known as yet, they exemplify differential expression regulated at the translational level during oogenesis in the mammal. The objectives to be pursued during the next award period include: (i) To generate a collection of different monoclonal antibodies targeted against ZP1-ZP3 to be used to study the structure, synthesis, and function of these glycoproteins. (ii) To estaslich a developmental timetable for the accumulation and secretion of ZP1-ZP3. (iii) To characterize the oligosaccharide domains of ZP1-ZP3. (iv) To develop a cell-free translation system for the synthesis of ZP1-ZP3 in vitro. (v) To characterize the intracellular state of mRNA encoding FP1-FP6 during oogenesis and early embryogenesis. (vi) To determine the degree of structural homology between FP1-FP6. (vii) To evaluate the stability of FP1-FP6 during early embryogenesis. The experimental approaches proposed include the use of metabolica and nonmetabolic radiolabeling protocols, monoclonal and polyclonal antibodies, sedimentation velocity centrifugation, cell-free translation, peptide mapping, plant lectings, glycosidases, one- and two-dimensional gel electrophoresis, fluorography, etc. Achievement of the objective presented here will represent a major step toward understanding the molecular basis of differential expression of two major classes of proteins during mammalian oogenesis and embryogenesis. In addition, these studies will greatly extend our knowledge of the structure and function of the zona pellucida.